unfolded logically atomic triple
The definition is a bit funky now to hack together something fast. See demo section for an example of application.
cc @dreyer@jung@robbertkrebbers@jjourdan
See merge request !7

This is more consistent with CAS, which also can be used on any value.
Note that being able to (atomically) test for equality of any value and
being able to CAS on any value is not realistic. See the discussion at
https://gitlab.mpi-sws.org/FP/iris-coq/issues/26, and in particular JH
Jourdan's observation:
I think indeed for heap_lang this is just too complicated.
Anyway, the role of heap_lang is not to model any actual
programming language, but rather to show that we can do proofs
about certain programs. The fact that you can write unrealistic
programs is not a problem, IMHO. The only thing which is important
is that the program that we write are realistic (i.e., faithfully
represents the algorithm we want to p
This commit is based on a commit by Zhen Zhang who generalized equality
to work on any literal (and not just integers).